A shadow assassin, shrouded in darkness with shadowy tendrils, riding a luminous, glowing griffon. The griffon's feathers radiate light, creating a stark contrast with the assassin's dark, almost invisible form. The scene is set in a moonlit mountain range, where the griffon's light pierces through the night, illuminating the rugged landscape. The moonlight enhances the dramatic contrast between the bright, glowing griffon and the shadowy, mysterious assassin, creating an ethereal and intense atmosphere.